ROCHESTER, NY-Current
strategies using high-dose chemotherapy
(HDC) and autologous
hematopoietic stem cell transplantation
(AHSCT) cure less than half
of in vivo patients with recurrent
or resistant lymphoma, and drug
resistance is the usual reason for
treatment failure. Attempts to increase
the dose of HDC/AHSCT
regimens to address this problem
have been limited by regimen-related
toxicity (RRT) to various
organs.
Gordon L. Phillips II, MD, director
of the Blood and Marrow
Transplant and Leukemia Program,
Strong Health and James P.
Wilmot Cancer Center, Rochester,
New York and colleagues from
the Medical College of Wisconsin
are addressing this problem by assessing
whether the cytoprotectant amifostine(Drug information on amifostine) (Ethyol) can reduce
RRT to permit augmentation of
the widely used BEAM (carmustine
[BiCNU], etoposide(Drug information on etoposide) (Ve-
Pesid), ara-C [cytarabine; Cytosar-
U], melphalan(Drug information on melphalan) [Alkeran]) regimen.
"BEAM is the most widely used
HDC/AHSCT regimen for lymphoma,
with acceptable nonrelapse
mortality rates of less than 10%.
[In BEAM, melphalan is given at
140 mg/m2]. Toxicity is consid-
ered acceptable if mortality rates
not due to relapse are less than
10%," Dr. Phillips said.
Melphalan Dose Escalation
In other studies, single-agent
melphalan doses of 200 to 220 mg/
m2 are the highest that can be
given-without cytoprotection-
owing to mucosal RRT. Adding
amifostine can permit increased
melphalan doses of 280 mg/m2,
Dr. Phillips said. "Thus, use of cytoprotectors
to minimize RRT of
existing regimens might permit
dose escalation, which might cure
more patients."
This concept is being tried in a
phase I melphalan dose-escalation
study using BEAM in which
melphalan is escalated in 20
mg/m2 increments in a cohort
design. Amifostine was given at
740 mg/m2 x 7.
Dr. Phillips reported results for
four evaluable patients of the
six enrolled (four with non-
Hodgkin's lymphoma, and two
with Hodgkin's lymphoma).
ALL (acute lymphoblastic leukemia)
engrafted and RRT was not
noted at the initial dose level; patient
accrual and dose escalation
continues. "The need for multiple
doses of amifostine was assumed
but is not proven," he said.
The investigators concluded
that multiple-dose amifostine can
be given without severe problems
but it is unclear if this reduces RRT
beyond the melphalan dose level
of 140 mg/m2.
